Dioxygen activation and pyrrole α-cleavage with calix(4)pyrrolato aluminates

• Verfasst von: Sigmund, Lukas M. [VerfasserIn]
• Verfasst von: Ehlert, Christopher [VerfasserIn]
• Verfasst von: Enders, Markus [VerfasserIn]
• Verfasst von: Graf, Jürgen [VerfasserIn]
• Verfasst von: Gryn’ova, Ganna [VerfasserIn]
• Verfasst von: Greb, Lutz [VerfasserIn]
• Titel: Dioxygen activation and pyrrole α-cleavage with calix(4)pyrrolato aluminates
• Titelzusatz: enzyme model by structural constraint
• Verf.angabe: Lukas Maximilian Sigmund, Christopher Ehlert, Markus Enders, Jürgen Graf, Ganna Gryn'ova, and Lutz Greb
• Jahr: 2021
• Umfang: 9 S.
• Fussnoten: First published: 06 May 2021 ; Gesehen am 29.11.2022
• Titel Quelle: Enthalten in: Angewandte Chemie. International edition
• Ort Quelle: Weinheim : Wiley-VCH, 1998
• Jahr Quelle: 2021
• Band/Heft Quelle: 60(2021), 28, Seite 15632-15640
• ISSN Quelle: 1521-3773
• DOI: doi:10.1002/anie.202104916
• Datenträger: Online-Ressource
• Sprache: eng
• Bibliogr. Hinweis: Parallele Sprachausgabe : deutschSigmund, Lukas M.: Disauerstoffaktivierung und Pyrrol-α-Spaltung mit Calix[4]pyrrolatoaluminaten
• Sach-SW: aluminum
• Sach-SW: dioxygen activation
• Sach-SW: intersystem crossing
• Sach-SW: metal-ligand cooperativity
• Sach-SW: structural constraint
• K10plus-PPN: 182388802X
• K10plus-PPN:
  Universitätsbibliothek
• Lokale URL UB: Zum Volltext

Abstract

The present work describes the reaction of triplet dioxygen with the porphyrinogenic calix[4]pyrrolato aluminates to alkylperoxido aluminates in high selectivity. Multiconfigurational quantum chemical computations disclose the mechanism for this spin-forbidden process. Despite a negligible spin-orbit coupling constant, the intersystem crossing (ISC) is facilitated by singlet and triplet state degeneracy and spin-vibronic coupling. The formed peroxides are stable toward external substrates but undergo an unprecedented oxidative pyrrole α-cleavage by ligand aromatization/dearomatization-initiated O−O σ-bond scission. A detailed comparison of the calix[4]pyrrolato aluminates with dioxygen-related enzymology provides insights into the ISC of metal- or cofactor-free enzymes. It substantiates the importance of structural constraint and element-ligand cooperativity for the functions of aerobic life.